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/* Signed and unsigned multiplication and division and modulus for CRIS.

   Contributed by Axis Communications.

   Written by Hans-Peter Nilsson <hp@axis.se>, c:a 1992.

   Copyright (C) 1998, 1999, 2000, 2001, 2002,

   2005 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it

under the terms of the GNU General Public License as published by the

Free Software Foundation; either version 2, or (at your option) any

later version.

In addition to the permissions in the GNU General Public License, the

Free Software Foundation gives you unlimited permission to link the

compiled version of this file with other programs, and to distribute

those programs without any restriction coming from the use of this

file.  (The General Public License restrictions do apply in other

respects; for example, they cover modification of the file, and

distribution when not linked into another program.)

This file is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; see the file COPYING.  If not, write to

the Free Software Foundation, 51 Franklin Street, Fifth Floor,

Boston, MA 02110-1301, USA.

   As a special exception, if you link this library with files, some of

   which are compiled with GCC, this library does not by itself cause

   the resulting object or executable to be covered by the GNU General

   Public License.

   This exception does not however invalidate any other reasons why

   the executable file or object might be covered by the GNU General

   Public License.  */

/* Note that we provide prototypes for all "const" functions, to attach

   the const attribute.  This is necessary in 2.7.2 - adding the

   attribute to the function *definition* is a syntax error.

    This did not work with e.g. 2.1; back then, the return type had to

   be "const".  */

#include "config.h"

#if defined (__CRIS_arch_version) && __CRIS_arch_version >= 3

#define LZ(v) __extension__ \

 ({ int tmp_; __asm__ ("lz %1,%0" : "=r" (tmp_) : "r" (v)); tmp_; })

#endif

#if defined (L_udivsi3) || defined (L_divsi3) || defined (L_umodsi3) \

    || defined (L_modsi3)

/* Result type of divmod worker function.  */

struct quot_rem

 {

   long quot;

   long rem;

 };

/* This is the worker function for div and mod.  It is inlined into the

   respective library function.  Parameter A must have bit 31 == 0.  */

static __inline__ struct quot_rem

do_31div (unsigned long a, unsigned long b)

     __attribute__ ((__const__, __always_inline__));

static __inline__ struct quot_rem

do_31div (unsigned long a, unsigned long b)

{

  /* Adjust operands and result if a is 31 bits.  */

  long extra = 0;

  int quot_digits = 0;

  if (b == 0)

    {

      struct quot_rem ret;

      ret.quot = 0xffffffff;

      ret.rem = 0xffffffff;

      return ret;

    }

  if (a < b)

    return (struct quot_rem) { 0, a };

#ifdef LZ

  if (b <= a)

    {

      quot_digits = LZ (b) - LZ (a);

      quot_digits += (a >= (b << quot_digits));

      b <<= quot_digits;

    }

#else

  while (b <= a)

    {

      b <<= 1;

      quot_digits++;

    }

#endif

  /* Is a 31 bits?  Note that bit 31 is handled by the caller.  */

  if (a & 0x40000000)

    {

      /* Then make b:s highest bit max 0x40000000, because it must have

         been 0x80000000 to be 1 bit higher than a.  */

      b >>= 1;

      /* Adjust a to be maximum 0x3fffffff, i.e. two upper bits zero.  */

      if (a >= b)

        {

          a -= b;

          extra = 1 << (quot_digits - 1);

        }

      else

        {

          a -= b >> 1;

          /* Remember that we adjusted a by subtracting b * 2 ** Something.  */

          extra = 1 << quot_digits;

        }

      /* The number of quotient digits will be one less, because

         we just adjusted b.  */

      quot_digits--;

    }

  /* Now do the division part.  */

  /* Subtract b and add ones to the right when a >= b

     i.e. "a - (b - 1) == (a - b) + 1".  */

  b--;

#define DS __asm__ ("dstep %2,%0" : "=r" (a) : "0" (a), "r" (b))

  switch (quot_digits)

    {

    case 32: DS; case 31: DS; case 30: DS; case 29: DS;

    case 28: DS; case 27: DS; case 26: DS; case 25: DS;

    case 24: DS; case 23: DS; case 22: DS; case 21: DS;

    case 20: DS; case 19: DS; case 18: DS; case 17: DS;

    case 16: DS; case 15: DS; case 14: DS; case 13: DS;

    case 12: DS; case 11: DS; case 10: DS; case 9: DS;

    case 8: DS; case 7: DS; case 6: DS; case 5: DS;

    case 4: DS; case 3: DS; case 2: DS; case 1: DS;

    case 0:;

    }

  {

    struct quot_rem ret;

    ret.quot = (a & ((1 << quot_digits) - 1)) + extra;

    ret.rem = a >> quot_digits;

    return ret;

  }

}

#ifdef L_udivsi3

unsigned long

__Udiv (unsigned long a, unsigned long b) __attribute__ ((__const__));

unsigned long

__Udiv (unsigned long a, unsigned long b)

{

  long extra = 0;

  /* Adjust operands and result, if a and/or b is 32 bits.  */

  /* Effectively: b & 0x80000000.  */

  if ((long) b < 0)

    return a >= b;

  /* Effectively: a & 0x80000000.  */

  if ((long) a < 0)

    {

      int tmp = 0;

      if (b == 0)

        return 0xffffffff;

#ifdef LZ

      tmp = LZ (b);

#else

      for (tmp = 31; (((long) b & (1 << tmp)) == 0); tmp--)

        ;

      tmp = 31 - tmp;

#endif

      if ((b << tmp) > a)

        {

          extra = 1 << (tmp-1);

          a -= b << (tmp - 1);

        }

      else

        {

          extra = 1 << tmp;

          a -= b << tmp;

        }

    }

  return do_31div (a, b).quot+extra;

}

#endif /* L_udivsi3 */

#ifdef L_divsi3

long

__Div (long a, long b) __attribute__ ((__const__));

long

__Div (long a, long b)

{

  long extra = 0;

  long sign = (b < 0) ? -1 : 1;

  /* We need to handle a == -2147483648 as expected and must while

     doing that avoid producing a sequence like "abs (a) < 0" as GCC

     may optimize out the test.  That sequence may not be obvious as

     we call inline functions.  Testing for a being negative and

     handling (presumably much rarer than positive) enables us to get

     a bit of optimization for an (accumulated) reduction of the

     penalty of the 0x80000000 special-case.  */

  if (a < 0)

    {

      sign = -sign;

      if ((a & 0x7fffffff) == 0)

        {

          /* We're at 0x80000000.  Tread carefully.  */

          a -= b * sign;

          extra = sign;

        }

      a = -a;

    }

  /* We knowingly penalize pre-v10 models by multiplication with the

     sign.  */

  return sign * do_31div (a, __builtin_labs (b)).quot + extra;

}

#endif /* L_divsi3 */

#ifdef L_umodsi3

unsigned long

__Umod (unsigned long a, unsigned long b) __attribute__ ((__const__));

unsigned long

__Umod (unsigned long a, unsigned long b)

{

  /* Adjust operands and result if a and/or b is 32 bits.  */

  if ((long) b < 0)

    return a >= b ? a - b : a;

  if ((long) a < 0)

    {

      int tmp = 0;

      if (b == 0)

        return a;

#ifdef LZ

      tmp = LZ (b);

#else

      for (tmp = 31; (((long) b & (1 << tmp)) == 0); tmp--)

        ;

      tmp = 31 - tmp;

#endif

      if ((b << tmp) > a)

        {

          a -= b << (tmp - 1);

        }

      else

        {

          a -= b << tmp;

        }

    }

  return do_31div (a, b).rem;

}

#endif /* L_umodsi3 */

#ifdef L_modsi3

long

__Mod (long a, long b) __attribute__ ((__const__));

long

__Mod (long a, long b)

{

  long sign = 1;

  /* We need to handle a == -2147483648 as expected and must while

     doing that avoid producing a sequence like "abs (a) < 0" as GCC

     may optimize out the test.  That sequence may not be obvious as

     we call inline functions.  Testing for a being negative and

     handling (presumably much rarer than positive) enables us to get

     a bit of optimization for an (accumulated) reduction of the

     penalty of the 0x80000000 special-case.  */

  if (a < 0)

    {

      sign = -1;

      if ((a & 0x7fffffff) == 0)

        /* We're at 0x80000000.  Tread carefully.  */

        a += __builtin_labs (b);

      a = -a;

    }

  return sign * do_31div (a, __builtin_labs (b)).rem;

}

#endif /* L_modsi3 */

#endif /* L_udivsi3 || L_divsi3 || L_umodsi3 || L_modsi3 */

/*

 * Local variables:

 * eval: (c-set-style "gnu")

 * indent-tabs-mode: t

 * End:

 */